A white light-emitting OLED device comprising: an anode and a cathode; at least four light-emitting layers provided between the anode and the cathode, wherein each of the four light-emitting layers produces a different emission spectrum when current passes between the anode and cathode, and such spectra combine to form white light; and wherein the four light-emitting layers include a red light-emitting layer, a yellow light-emitting layer, a blue light-emitting layer, and a green light-emitting layer, arranged such that: i) each of the light-emitting layers is in contact with at least one other light-emitting layer, ii) the blue light-emitting layer is in contact with the green light-emitting layer, and iii) the red light-emitting layer is in contact with only one other light-emitting layer.